Typically, wind turbines include a rotor having a plurality of rotor blades mounted thereon; a drive train and a generator housed in a nacelle; and a tower. The nacelle and the rotor are typically mounted on top of the tower. In operation, the plurality of blades of the rotor receive energy from the wind and convert the wind energy into a rotational torque that is used to drive the generator, which is rotationally coupled to the rotor through the drive train. Aeroelastic wind turbine blades have been investigated for their potential ability to increase the energy production for a wind turbine by forming blades that passively twist to reduce loads created by flow-field perturbations (turbulence, shear, yaw, etc.), thereby making it possible to design larger rotors for normal operating conditions that will increase the output of the wind turbine.
Known aeroelastic blades include those having at least a backward sweep relative to a reference line extending along the blade length on an outboard section of the blades. The backward sweep enables aerodynamic forces to act at a distance from the local structural axis of the blade, which, in turn, creates a local twisting moment about the structural axis. The twisting moment naturally gives rise to a self-correcting induced twist of the blade toward a lower aerodynamic angle of attack, thus passively averting abnormally high lift forces during off-normal conditions.